ANSYS HFSS Features

ANSYS HFSS software contains the technology, solvers and capabilities needed to model RF and microwave as well as signal- and power-integrity issues.

EM Solver Technologies

HFSS offers multiple state-of the-art solver technologies for high-frequency electromagnetic field simulation. Powerful solvers based on the proven finite element method, the well-established integral equation method, or combined hybrid techniques deliver the most advanced computational methods available in an easy to use design environment.

HFSS Interface

HFSS 3D Modeler

The 3-D interface enables users to model complex 3-D geometry or import CAD geometry. Typically, the 3-D mode is used to model and simulate high-frequency components, such as antennas, RF/microwave components and biomedical devices. Engineers can extract scattering matrix parameters (S,Y, Z parameters), visualize 3-D electromagnetic fields (near- and far-field), and generate ANSYS Full-Wave SPICE models that link to circuit simulations. The modeler includes parametric capability to easily allow an engineer to define variables and make design variations for design trends, optimization sensitivity and statistical analysis.

 .

hfss-interface-image-1-sm

 .hfss-interface-image-2-sm

 .3-D models can easily be created using the 3-D solid modeler

 .hfss-interface-image-4-sm

Complex multi-layer PCB with overlay of 3-D mesh generated with phi meshing technology

 .

HFSS 3-D Layout

HFSS 3-D Layout is ideal for designers who work in layered geometry or layout of high-speed components, including on-chip embedded passives, IC packages and PCB interconnects. These types of designs can be easily modeled in the HFSS electrical layout environment while, at the same time, simulating for all 3-D features, such as trace thickness and etching as well as bondwires, solder bumps and solder balls. Geometry such as trace width can be easily parameterized and optimized using the integrated ANSYS Optimetrics tool in the HFSS 3-D layout interface.

With HFSS 3-D Layout modeling, material properties, port setup and boundary conditions are set automatically in the layout interface. An advanced phi meshing is included in the 3-D electrical CAD/layout. This specialized meshing technology is optimized for meshing silicon substrates, redistribution layers, electronic packages and printed circuit boards. It delivers incredible speed with reliability and capacity to the meshing process of these complex structures.

Models created in Cadence Design Systems, Mentor Graphics and Zuken can be imported directly to HFSS without any further setup. The package layout can be parameterized to compute tuning and sensitivity to understand impedance variations due to process. The interface supports traditional ECAD primitives, such as padstacks, traces, wirebonds and solderballs; it propels a new state-of-the-art solution for digital and RF engineers.

 .

hfss-interface-image-6-sm

HFSS 3-D Layout Interface Changes

  • Fully automated HFSS port creation and setup
  • Layout, stackup and padstack editors
  • Parametric design environment
  • Maintain trace characteristics and nets from layout
  • Hierarchical design: chip–package–board

     .

Cadence-Specific HFSS 3-D Layout

HFSS 3-D layout technology enables users of Cadence software to set up ready-to-solve chip, package and PCB simulations directly from Allegro® Package Designer, Allegro PCB Designer, SiP Digital Layout, or Virtuoso® Analog Design Environment for analysis in HFSS. All the necessary HFSS setup steps (geometry and net selection, material properties, excitations and boundary conditions) are completed in Cadence software and transferred to HFSS for solving the electromagnetic field and S-parameters via a single click. Users never leave the Cadence interface.

 .

Circuit Simulation Extensions

ANSYS RF Option

Adding the ANSYS RF option to HFSS creates an end-to-end high-performance RF simulation flow including harmonic balance circuit simulation for nonlinear microwave circuit amplifier analysis, 2.5-D method of moments solver integrated in the HFSS 3-D Layout interface and filter synthesis; it includes DC, transient, oscillator, load-pull and envelope circuit analysis engines.

  • Circuit analyses
    • Linear network analysis (included with HFSS)
    • DC analysis with multiple continuation options
    • Multi-tone harmonic balance analysis
  • Shooting method option
    • Oscillator analysis
  • Autonomous plus driven sources option
    • Time varying noise and phase noise analyses
    • Envelope analysis
  • Multi-carrier modulation support
    • Load pull analysis and model support
    • Periodic transfer function analysis

hfss-rf-option

 .

ANSYS SI Option

HFSS combined with the ANSYS SI option is ideal for analyzing signal integrity, power integrity and EMI issues caused by shrinking timing and noise margins in PCBs, electronic packages, connectors and other complex electronic interconnects. HFSS with the SI option can handle the complexity of modern interconnect design from die-to-die across ICs, packages, connectors and PCBs. By leveraging the HFSS advanced electromagnetic-field simulation capability dynamically linked to powerful circuit and system simulation, engineers can understand the performance of high-speed electronic products long before building a prototype in hardware. This approach enables electronics companies to achieve a competitive advantage with faster time to market, reduced costs and improved system performance.

The ANSYS SI option adds transient circuit analysis to HFSS. This allows engineers to create high-speed channel designs that include the driving circuitry as well as the channel. The driving circuitry can be transistor level, IBIS-based or ideal sources. When performing an analysis on these channels, a user can select from a variety of analysis types:

  • Linear network analysis (included with HFSS)
  • Transient analysis
  • QuickEye and VerifEye analyses for fast eye generation in high-speed channel design, bathtub curves, jitter and eye masks
  • Monte Carlo analysis supporting Spectre® and HSPICE® functionality
  • DC analysis with automated convergence
  • Dynamic links with ANSYS Q3D Extractor and ANSYS SIwave
  • IBIS-AMI analysis and model support

hfss-si-option

DDR3 simulation performed with the ANSYS SI option, showing DQ, DQS and timing eye patterns.

Advanced Finite Antenna Array Simulation

ANSYS HFSS software allows calculation of finite-sized phased-array antennas with all electromagnetic effects, including element-to-element coupling, and critical array edge effects.

The traditional approach for simulating large phased-array antennas is to approximate antenna behavior by assuming an infinitely large array. In this technique, one or more antenna elements are placed within a unit cell with periodic boundary conditions on the surrounding walls that mirror the fields to create an infinite number of images in two directions. For many years, engineers have used the periodic boundary condition capability in HFSS to simulate infinitely large phased arrays to extract per-element impedance and elemental radiation pattern, including all mutual coupling effects. The method is especially useful for predicting array blind zones that can occur under certain scan conditions. The method, however, is unable to predict behavior of finite-sized arrays that the array edge affects.

 .

hfss-antenna-finite-array

Far field antenna patterns of finite array calculated with HFSS. Graph on right shows effect of finite array (solid lines) size on sidelobes when compared to infinite array (dashed lines).

 .

The finite-sized array simulation technology leverages the repeating nature of array geometries. It can be used with the HPC domain decomposition capability to obtain a very fast solution time for large finite-sized arrays. This technology makes it possible to perform complete array analysis to predict all mutual coupling, scan impedance, element patterns, array patterns and array edge effects.

 .

hfss-3D_1

Phased-array antenna electric field distribution with far-field radiation pattern simulated by finite antenna-array capability in HFSS

Automatic Adaptive Meshing

A key benefit of HFSS is its automatic adaptive meshing techniques for which you need to specify only geometry, material properties and the desired output. The meshing process uses a highly robust volumetric meshing technique and includes a multi-threading capability that reduces the amount of memory used and speeds simulation time. This proven technology eliminates the complexity of building and refining a finite element mesh and makes advanced numerical analysis practical for all levels of your organization.

hfss-antenna-automated-adaptive-meshing

Automatic adaptive meshing concentrates elements where needed based on field requirements, thus providing an accurate and efficient solution.

Mesh Element Technologies

ANSY HFSS software utilizes tetrahedral mesh elements to determine a solution to a given electromagnetic problem. These mesh elements in combination with the adaptive mesh procedure create a geometrically conformal, and electromagnetically appropriate, mesh for any arbitrary HFSS simulation. This ensures that HFSS will provide the highest-fidelity result for any given simulation. In addition to creating standard first-order tetrahedral mesh, HFSS can employ zero-order and second-order elements as well as a mixture of elements of different orders. Using mixed-order elements enables HFSS to assign an element order based on the element size, which creates an exceptionally efficient mesh and overall solution process.

HFSS also allows the use of curvilinear elements. These elements are perfectly conformal to any associated curved surface. This then provides the highest degree of accuracy possible, as absolutely no assumptions or tessellation are performed.

hfss-mesh-elements

Conformal curvilinear adapted mesh

High-Performance Computing

ANSYS HPC computing technology delivers optimum computational power for HFSS simulations. With ANSYS Electronics HPC, you can solve ever-larger, more complex electromagnetic field simulations and leverage networked computer resources to achieve faster solutions. Advanced features include:

  • Multi-level HPC: A designer can leverage more nodes of a compute cluster or cloud environment to accelerate  design efforts through combined distribution of design parameters, frequencies and multi-core/multi-domain EM solvers.
  • Distributed direct matrix solver allows the designer to leverage computer memory across networked computers, resulting in the ability to solve larger, more complex geometry.
  • Distributed domain solvers: This increase in HPC capability provide further scalability and speed for simulations including:
    • Improved parallelization of hybrid simulations (for example, FEBI boundaries and regions) through matrix decomposition
    • Improved parallelization domain decomposition simulations for multi-port analysis (for exaample, antenna co-site)
  • GPU support for ANSYS HFSS transient: The HFSS transient solver can leverage GPU computing resources to achieve greater simulation speed.

     .

hfss-3D_2

Electric field in cavity filter simulated by HFSS

Advanced Broadband SPICE Model Generation

ANSYS Full-Wave SPICE, included in ANSYS HFSS, provides frequency-dependent SPICE models for accurate time-domain simulation in time-domain circuit analysis tools. ANSYS Full-Wave SPICE models can be created for use with ANSYS Nexxim, HSPICE®, Spectre® RF and MATLAB®. Full-Wave SPICE produces highly accurate, high-bandwidth SPICE models at the touch of a button. This capability enables you to design electronic and communication components while taking Gigahertz-frequency effects into account.

Optimization & Statistical Analysis

ANSYS Optimetrics is a versatile optional software program that adds parametric, optimization, sensitivity and statistical analysis capabilities to the HFSS 3-D interface. Optimetrics automates the design optimization process for high-performance electronic devices by quickly identifying optimal values for design parameters that satisfy user-specified constraints.

Coupled to ANSYS electromagnetic field simulation software, Optimetrics delivers optimized designs that favorably impact the bottom line.

 .

optimetrics_home_th

hfss-optimization-statistical-2-sm

 .

Features

Parametric analysis

  • User-specified range and number of steps for parameters
  • Automatic analysis of parameter permutations
  • Distributed solve (cost option)
    • Automated parser management across multiple hardware platforms and reassembly of data for parametric tables and studies

Analytic Derivatives

  • Direct matrix level calculation of SYZ parameter derivatives with respect to user selected design and project variables; very fast calculation of design sensitivity in one simulation

syz-parameter-sensitivity-bg

SYZ parameter sensitivity as a function of frequency for six distinct design parameters of dual-band GSM phone antenna

 .

Optimization

  • User-selectable cost functions and goal objective
    • Quasi-Newton method
    • Sequential nonlinear programming (SNLP)
    • Integer-only sequential nonlinear programming
  • Automatic analysis of parameter variants until optimum goal obtained

Sensitivity analysis

  • Design variations to determine sensitivities
    • Manufacturing tolerances
    • Material properties

Tuning

  • User-controllable slide-bar for real-time tuning display and results

Statistical analysis

  • Design performance distribution versus parameter values